Blade-grinder



(No Model.)l

` E. B. ALLEN.`

BLADE GRINDER.

No. 598,333Hl Patented Feb. 1, 1898.

EDWARD B. ALLEN, lOF ELIZABETH, NEW JERSEY, ASSIGNCR TO THE SINGER MANUFACTURING COMPANY, OF NEV JERSEY.

.BLADEGRINDER.-

-SPECIFILCA'IION forming part of Letters `Patent No. 598,333, dated February 1, 1898. Applicant nea June 15.1897. serai No. 640.866. `du model.)

.To all whom it may concern.'

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Blade-Grinders, of which the following is a specification, reference being had therein to the accompanying drawings. i

This invention relates to a grinder more especially intended for sharpening the shear-A blades of sewing-machine trimmers, although adapted for other purposes.

The shear trimmer-blades, for sharpening which my improved grinder is more particularly designed, are, when in use, pivotally mounted, so that when adjusted to compensate for wear they are simply turned on their pivots, and it is therefore essential that the cutting edges thereof should always preserve certain tangential lines relative to their pivotal centers, as also that the bevels of their edges should always preserve certain angles, all of which objects are so reliably secured by my improved grinding device that it is practically impossible for unskilled operators in the use of my invention to grind the blades wrong.

Figure l is a plan view of my improved grinder, and Figs. 2 and 3 are side and end views, respectively, of the same.

A denotes a base-plate to be attached to a work bench or table, and B is a standard adj ustably secured to said base-plate and provided with bearing arms or portions b.

C is a shaft journaled in the bearing-arms h and provided at one end with a driving-pulley c and at its opposite end with an emery or other suitable grinding wheel D, clamped to said shaft in any well-known manner.

The base-plate A is provided with longitudinal ribs or guideways a, on which is mounted a sliding carriage E, having an inclined face, against which is placed the blades, as F, to be sharpened. The guideways a are parallel to the line of the longitudinal axis of the shaft C, so that the carriage E is movable backand forth on said guideways in a plane transverse to the plane of rotation of the grinding-wheel l D, carried by said shaft, when a blade is being sharpened.

which the stem of the screw G passes, so that the said blade is thereby pivotally mounted l on said screw- The blade F is preferably yieldingly held against the inclined face of the carriage E by a spring H, interposed between the head of the screw G and the said blade.

G is an adjusting-screw tapped in a portione of the carriage E, the lower end of said screw impinging against the blade F, so that by turning said screw said blade will be turned slightlyon the screw G as a pivot to bring the tangentially-arranged cutting edge f of the said blade against the grindingwheel D.

In the use of my grinder the attendant mounts the blade to be ground on the carriage, as shown, and then adjusts the screw G to bring the edge f of the blade against the revolving grinding-wheel. The carriage E is now moved back and forth by the attendant in'its guideways a and the screw G' turned down-until the desired sharpness of edge is secured. The inclined position of thebladeholding part of the carriage and the certain guiding of the latter on its ways insure an even bevel and a uniform straight tangential form and disposition of the cutting edge of the blade being ground, and it will therefore be practically impossible for the most unskilled attendant to grind the blades wrong.

As the grinding-wheel wears away the standard B may be adj usted forward or toward the blade F, as may be necessary.

Having thus described my invention, I claim and desire to secure by Letters Patentl. Ina grinder,the combination with a suitable base provided with a guideway or guideways, of a sliding carriage mounted thereon and having an inclined blade-supporting part, means for pivotally mounting ablade to be ground on said inclined blade-supporting part of said carriage, a rotating grindingwheel, and a screw-adjusting device for forcing the edge of the pivotally-mounted blade x ICO to be ground into proper grinding contact With said Wheel, the said carriage, With the pivotally-mounted blade, being movable back land forth on said guidevvays in a plane trans- Verse to the plane of rotation of said grinding-Wheel.

2. In a grinder, the combination with asuitable base provided with a guideway or guide- Ways, of a sliding carriage mounted thereon and having an inclined blade-supportin g part, means for pivotally and yieldingly mounting a blade to be ground on said inclined bladesupporting part of said carriage, a rotating v grinding-Wheel, and a screw-adjusting device for forcing the edge of the pivotallymounted blade to be ground into proper grinding contact with said Wheel.

3. The combination with the ribs or guide- Ways 0 of the standard B adj ustably mounted on said base, the shaft C journaled in said standard and provided With the driving-pulley c and the grinding-Wheel D, and the sliding carriage E movable on said guideways in a plane transverse to the plane of rotation of said grinding-Wheel, said carriage having an inclined blade-supporting face provided With the blade-holding pivot-screw G and bladeadjusting screw G.

4. The combination With the base A provided With the ribs or guideways a, of the standard B adjustably mounted on said base, the shaft C journaled in said standard and provided-With the driving-pulley c and the grinding-Wheel D, and the sliding carriage E movable on said guideways and having an inclined blade-supporting face provided with the blade-holding pivot-screw G and bladeadjusting screw G', said blade-holding screw being encircled by a spiral spring to yieldingly press the blade being ground against said grinding-Wheel.

In testimony whereof I affix my signature in presence of two Witnesses.

EDWARD E. ALLEN.

Witnesses:

HENRY CALvER, JOSEPH F.y J AQUITH. 

